Multi-stream thin edge orifice disks for valves

ABSTRACT

A dual stream thin edge orifice disk is defined as a disk having a pair of orifices positioned to direct the flow of fluid from the interior portion of a valve into two different streams. The dual streams may be parallel or typically diverge at an angle for directing the stream to two adjacent engine valves in the situation wherein the valve is an electromagnetic fuel injector for an internal combustion engine. To have the dual stream flow in a direction that is not parallel, the area of the disk surrounding the dual orifices is embossed and the orifices are positioned along the sides of the embossment between the base and the apex thereof. The manufacturing of the accurately sized orifices in the disk is accomplished by means of a progressive die. One of the stations of the die provides a coining operation on the orifice. Such coining operation is adjustable by means of a micrometer adjustment. Another of the stations provides a forming operation wherein an embossment is formed in such a manner that the orifices are positioned on the sides of the embossment between the base and the apex. In another embodiment of a valve, a pair of dual orifice disks are position adjacent each other with the orifices of the first disk overlapping the orifices of the second disk.

This application is a division of application Ser. No. 137,497 filedDec. 23, 1987 now Pat. No. 4,854,024, dated Aug. 8, 1989, which is acontinuation-in-part application of U.S. Ser. No. 937,658 entitled"Manufacturing Process for Manufacturing Thin Edge Orifice Disks forFuel Injectors" filed on Dec. 4, 1986 by Grieb et al. which is nowabandoned.

This invention relates to multi-stream thin edge orifices for disks forvalves and more particularly to the manufacturing of thin disks havingat least two thin edge orifices therein for use in fuel injectionvalves.

BACKGROUND OF INVENTION

Fuel injection systems for motor vehicles operate to provide accurateamounts of fuel to each cylinder in order to achieve a predeterminedfuel/air ratio for purposes of combustion and operability of the engine.Most fuel injection systems are a combination of electronics andelectromechanical devices. The responsibility of the electronics is tocalculate the amount of fuel to be delivered to the cylinder and one ofthe electromechanical devices, the fuel injector, operates to deliverthe calculated amount of fuel to the cylinder.

Most fuel injectors are actuated by a precise time length electricalpulse and during the actuation time, fuel is supplied from the injector.Both the opening time and the closing time of the injectors arecontrolled. Many factors influence the amount of fuel supplied by theinjector. Some of these factors are the fuel pressure, the "lift" of theinjector needle, the speed in which the injector valve opens and thespeed in which the injector valve closes, the length of the actuationpulse, the size of the orifice or orifices through which the fuel flows,etc.

Depending on the type and style of fuel injector, there is a platemember between the valve seat and the end of the injector which directsthe flow of fuel. Contained on this plate member is one or more orificesof precision size. Once the valve is opened for the predetermined periodof time, the orifice or orifices control the amount of fuel actuallydischarged from the injector. Because of manufacturing techniques, the"cleanness" and the size of the orifices require each injector to beadjusted for the proper flow rates. This is a labor intensive task andtherefore increases the cost of the injector.

Previous methods of manufacturing orifice disks have used ElectricalDischarge Machines (EDM) for cutting the orifice by means of acontrolled electrical discharge. Other methods have used laser beams,photo-etching, or basic drill and ream techniques to form the orifice.All of these, while they have been successful to some degree, have notbeen without high unit cost.

Modern fuel injectors have no adjustments to be made after the injectoris assembled and therefor the size of the orifice or orifices must beheld to very close tolerances. This is typical of all orifices in everyfuel injector and problems in flow rates are still present. To furthersolve the problem of maintaining desired flow rates, with all otherfactors in the fuel injector design remaining unaffected, themanufacturing apparatus and process for manufactured an orifice disk forfuel injectors was developed.

SUMMARY OF INVENTION

A process for manufacturing a dual orifice disk for valves uses aprogressive die means having several stations through which the diskstock is transported. The first two stations in the die means operate topunch the necessary pilot holes to hold the stock in the correctrelationship to the orifice punch and to punch the approximate hole sizeof the first orifice.

The stock is progressed to a second station where the orifice is shavedof any extra material which is residual as a result of the punching. Thenext two stations are for punching and if necessary, shaving the secondorifice. The following two succeeding stations contain coin puncheswhich are controlled by micrometer adjusting means for first coining oneof the orifices and then coining the other of the orifices. If desired,the coining process can be repeated for the backside of the disk for thetwo orifices.

The next stations in the progressive die operate to create the outsidediameter pattern of the disk so the disk can be carried in the strip oras an option to remove the complete disk from the stock. Once the diskis removed from the stock, it is transported to the injector assemblyand located between the valve seat and a back-up washer at the end ofthe injector. The micrometer adjusting means is controlled as a functionof the final flow testing of the disk and operates to affect thecoefficient of discharge of the orifice.

The orifice disk in the preferred embodiment is a thin disk having dualorifices. The orifices are characterized as thin edge orifices. The diskis fabricated from stainless steel to reduce or avoid contamination ofthe orifices with the liquid flowing therethrough. The orifices have thetop edge coined to a predetermined dimension for maintaining thecoefficient of discharge to achieve the desired fluid flow through theorifice disk.

It is a principal advantage and object of the invention to producemultiple burr free orifices in thin material stock. It is a furtheradvantage of the invention to produce burr free orifices in a thinmaterial disk stock in high volume production. It is yet anotheradvantage of the invention to provide the manufacturing capability ofadjusting the coining punch to maintain the required fluid flow qualityof the orifices. It is another advantage of this invention is to be ableto compensate for manufacturing variables, thus making thismanufacturing process extremely economical. It is yet another advantageof this invention to produce valves having multi-stream flows of fluidfrom the valve. It is still another advantage to produce a single dualorifice disk for having two divergent fluid flows from a valve whereinthe disk has an embossment and each orifice is fully positioned on thesides of the embossment.

DESCRIPTION OF THE DRAWINGS

These and other advantages and objects will become apparent from thefollowing detailed description taken in conjunction with the drawings inwhich:

FIG. 1 is a plan view of the orifice disk;

FIG. 2 is a partial sectional view of an injector illustrating therelationship of the orifice disk and the valve seat;

FIG. 3 is a graph of flow rate vs micrometer adjustment for the orificesmanufactured according to the invention herein;

FIG. 4 is a plan view of the strip layout of the stock from which thedisk is manufactured showing the several progressive steps;

FIG. 5 is a plan view of an orifice disk having two orifices;

FIG. 6 is a partial sectional view of an valve illustrating therelationship of two dual orifice disks and the valve seat;

FIG. 7 is a enlarged view of the area of the circle in FIG. 6 showingthe relationship of the two dual orifice disks;

FIG. 8 is a plan view of an orifice disk having two orifices and anembossment;

FIG. 9 is a section view of the orifice disk taken along line 9--9 ofFIG. 8 showing the relationship between the orifices and the embossment;

FIG. 10 is a partial sectional view of an valve illustrating therelationship of the dual orifice disk and the valve seat.

DETAILED DESCRIPTION

Referring to the FIGURES by the characters of reference, there isillustrated in FIG. 1 an orifice disk 10 as may be used in fuelinjectors 12 or any other type of valve. The disk 10 is located betweenthe valve seat 14 and the outlet 16 of the injector 12 and held in placeby means of back-up washer 18 holding the disk 10 in spaced relationshipwith the end of the injector body 20 as illustrated in the sectionalview of FIG. 2.

The injector 12 comprises a body having a fuel passageway 22 along theaxis thereof. The body of the injector 12 is secured to a housing bymeans of the end of the housing being rolled over to hold the body tightagainst a spacer and a seal. The spacer is fabricated according to themethod taught in U.S. Pat. No 4,610,080 issued on Sept. 9, 1986, to T.E. Hensley entitled "Method For Controlling Fuel Injector Lift" andassigned to the assignee of this application. The housing contains anelectromagnetic circuit for moving an armature member which is connectedto a needle 24 to a pole piece. The axis of the pole piece has a fluidpassageway in line with the fuel passageway 22 in the body 20, providingfor the flow of fuel from an inlet to the valve seat 14. A spring meansbiases the armature member and the needle 24 into the valve seat 14 toclose the injector 12.

The needle 24 of the injector 12 is controlled by means of anelectromagnetic circuit, not shown, and is under the control of fuelinjection pulse as may be generated from electronic circuitry inCludinga microprocessor. When the injector 12 is closed, the needle 24 of theinjector 12 is biased against the valve seat 14 to prevent any flow ofliquid such as gasoline from the injector 12. The valve seat 14, asillustrated, has a conical section for mating with the needle 24 and anaxial extending aperture 26. At the output of the aperture 26, theorifice disk 10 is located with the orifice 28 centered along the axisof the valve seat 14. As the liquid or fuel is discharged from theoutlet 16 injector 12, the fuel fans out in a conical stream.

The characteristic of the flow rate depends in a large measure on thecoefficient of discharge, C_(D), of the orifice 28. This coefficient isthe product of the coefficient of contraction C_(C) and the coefficientof velocity C_(V) according to the following formula:

    C.sub.D =(C.sub.C)(C.sub.V)

The higher the coefficient of discharge, the more the actual flow out ofthe orifice 28 is equal to the ideal flow out of the orifice 28. Thisequates to:

    Q=(C.sub.D)(Q.sub.i)

where Q is the actual discharge flow and Q_(i) is the ideal dischargeflow.

The orifice disk 10 of FIGS. 1 and 2 is a thin stainless steel diskhaving an orifice 28 with a diameter of 0.0185 inches (0.4699 mm). Inthe preferred embodiment, the thickness of the disk 10 is 0.003 inches(0.0762 mm) and the main dimension or diameter of the disk 10 is 0.248inches (6.32 mm) giving a ratio of thickness to the main dimension of1:80. The length/diameter ratio of the orifices is less than 0.25. Bymeans of the manufacturing apparatus to be described herein, the orifice28 is punched with a known punch size and then coined within acceptablebounds to produce a desired thin edge orifice flow within a flow rangewithout changing punch and die bushings.

FIG. 4 illustrates the plan view of the strip 30 layout of the stockfrom which the orifice disk 10 of FIG. 1 is fabricated. As will bedescribed herein, the disk 10 may be manufactured in a progressive dieand the view of FIG. 4 illustrates the results of several of thestations of a progressive die. The stock is procured and placed in thedie. The first station 34 illustrates a pair of pilot holes 32 punchedthrough the stock. These pilot holes 32 are well outside the outsidediameter of the finished disk 10 of FIG. 1 and function to locate andhold the strip 30 in the succeeding stations of the die to maintain therelationship between the orifice 28 and the outer perimeter of the disk10.

The next station 36 illustrates the result of punching the orifice 28 inthe strip 30 material. This is accomplished by means of a punch havingits size held to very tight tolerances. After the orifice 28 is punched,the strip 30 moves to a succeeding station 38 where the orifice 28 isshaved, if necessary, of any extra material which is residual as aresult of the punching operation. Next the strip 30 is moved to astation 40 where one of the surfaces of the orifice 28 is coined. Insome instances it is advisable after coining the one surface to move thestrip 30 to another station where the opposite surface of the orifice 28is coined. As will be described, the coining is performed by means of acoining die controlled by a micrometer adjustment. In the followingstation 42, the outside diameter "hot dog" pattern 44 of the disk 10 isblanked and carried in strip 30. As an option, station 46 the disk 10can be blanked from the strip 30 when making individual disks. Theoption to punch the "hot dog" pattern 44 and carry the disk in the stripor to blank the disk completely out of the strip 30 is dictated bywhether or not the disk will be assembled into the valve bodyautomatically or manually.

By means of the micrometer adjustment, the depth of the coining punch iscontrolled and the end result is the control of the flow of fuel fromthe orifice 28. FIG. 3 illustrates the relationship between theadjustment of the micrometer along the "x axis" 48 and the flow out of athin edge orifice disk 10 fabricated in accordance with the processherein along the "y axis" 50. It is thus seen by the curve 52 that for avery small change in the adjustment of the micrometer, the flow changesin a linear manner. It has been found that after initial die run in, thenecessity to adjust the coil punch is very infrequent as the thin edgeorifice 28 size and characteristics remain constant for a fixed orificeflow other than compensating for the wear and material variation.

FIG. 5 illustrates an orifice disk 53 similar to the disk 10 illustratedin FIG. 1 with the sole exception of having at least two spaced apartorifices 54, 55. The two orifices 54, 55 are formed in the same manneras the orifice 28 in the disk 10 in FIG. 1; in that the orifices 54, 55are punched in a station of a progressive die as stated for the orifice28. After punching, the orifices may be coined in succeeding stations orthe second of the two orifices may be punched after the first orifice iscoined and then the second orifice is coined after it is punched. In thepreferred embodiment, both orifices 54, 55 are punched and then bothorifices are coined. A typical diameter of each orifice is 0.014 inches(0.3556 mm) and with a 0.003 inch (0.0762 mm) thick disk, thelength/diameter ratio of each orifice is 0.21. If there is any extramaterial as a result of the punching operation, the orifices may beshaved before coining.

FIG. 6 illustrates a partial sectional view of a valve having two dualorifice disks 53, 57 of FIG. 5. In FIG. 6, the two disks 53, 57 arepositioned between the valve seat 14 and the backup washer 18 andfunction to direct the flow of the fluid through the valve output 16into two divergent streams from the valve. As further illustrated inFIG. 7, the orifices 54, 55 in the two disks 53, 57 have a differentaxial spacing. The orifices 54, 55 in the top disk 53 are spaced closertogether than in the bottom disk 57. In another embodiment, which is notillustrated the two disks are identical to the disk 53 but when they arepositioned in the valve, they are rotated slightly with respect to eachother. In either embodiment, the flow through the top disk 53 orificesis further directed by the bottom disk 57 and the resultant is adivergent flow.

FIGS. 8 and 9 illustrates an orifice disk 56 similar to that illustratedin FIG. 5 with the sole exception of an embossment 58 which in thepreferred embodiment is concentric with the axis of the disk 56. Theembossment 58, which may be any desired shape, is in the preferredembodiment conical in shape. The angle 60 of the apex of the conicalshape has an angular value which is the complement of the angle 62formed by the intersecting inside the valve of the axis of each of thetwo orifices 54, 55. In the preferred embodiment this angle 60 issubstantially 156°.

The embossment 58 is formed in the progressive die either before orafter the coining operation. The embossment is of such a depth that bothorifices are positioned along the sides of the embossment between thebase and the apex thereof.

FIG. 10 is a partial sectional view of a valve having the two dualorifice disk 56 of FIG. 8. In FIG. 10, the dual orifice disk 56 ispositioned between the valve seat 14 and the backup washer 18 andfunctions to direct the flow of the fluid through the valve output 16into two divergent streams from the valve.

It is to be understood that in either embodiment illustrated in FIG. 6or 10, orientation of the disk in the valve may be critical and a meansof indexing the location of the orifices to an external location on thevalve will be used. If it is an electromechanical valve, the orientationmay be relative to the connection for the wires. Another form oforientation maybe to a special surface on the external surface of thevalve.

Many changes and modifications in the above described embodiment of theinvention can, of course, be carried out without departing from thescope thereof. Accordingly, that scope is intended to be limited only bythe scope of the appended claims.

We claim:
 1. In a valve for controlling the flow of a fluid having avalve body with a fluid passageway therein terminating in an outlet, avalve seat in the fluid passageway, a valve needle biased to seat on thevalve seat to close the passageway, a backup-washer between the valveseat and the outlet, the improvement comprising:a thin disk memberhaving at least two orifices therein, the length/diameter ratio of eachof said orifices is less than 0.25 and the axises of said orificesintersecting in the valve opposite the outlet for directing a number offlow streams of fluid equal to the number of orifices in a divergingpattern from the outlet of said valve said disk member positionedbetween the valve seat and the backup-washer and operable to control theflow rate of the fluid from the valve body.
 2. In a valve according toclaim 1 wherein said axises of said orifices intersecting in the valveat an included angle of less than 30°.